Endpoint Vulnerability

CORS preflight is bypassed when non-standard Content-Type headers are received

Description

Security researcher Shinto K Anto reported an issue with cross-origin resource sharing (CORS) 'preflight' requests when receiving certain Content-Type headers. This is due to an error in implementation resulting in trying to process multiple media types when they are returned in the Content-Type headers from a server. This is disallowed in the CORS specification and results in a simple instead of a 'preflight' request, leading to potential same-origin policy violation.

Affected Products

Firefox ESR

References

CVE-2015-7193,